Abstract: A pleural drainage probe which consists of a flexible tube into which a guide element may be inserted and which is provided with at least two axially separated inflatable peripheral chambers which are both connected to the outside via independent capillary conduits made in the wall of the tube, each of said conduits, after branching close to the end of the tube, terminating in broadenings which enable the air supply means to be connected, each of the branches being provided with an anti-return valve.